Singers Demi Lovato and Taio Cruz made the announcement Tuesday in Los Angeles.

Eminem and Bieber are each up for favorite pop/rock artist and album, and the rapper is also nominated for favorite artist and album in the rap/hip-hop category. Both Bieber and Eminem are also nominated for artist of the year, along with Perry, Ke$ha and Lady Gaga.

Lady Antebellum is nominated for favorite band, duo or group in the pop/rock and country categories, along with favorite country album, favorite adult contemporary artist and the breakthrough artist award.

Music fans can choose winners in the show's nine categories by voting online. Nominees were selected based on chart ratings for sales and radio and Internet play.

The American Music Awards will be presented Nov. 21 at the Nokia Theatre and broadcast live on ABC. Bon Jovi, Usher and P!nk are slated to perform.